Systems and methods for stillage fractionation

ABSTRACT

Systems and methods for fractionating whole stillage from an ethanol production facility are provided. Whole stillage undergoes a separation of its liquid portion (thin stillage) from the solid portion (fiber cake). In some embodiments, the solids and liquids in whole stillage may be separated utilizing a screening centrifuge. The fiber cake may be dried to generate a high fiber animal feed. The thin stillage may be provided to a three-phase separator for separation into an oil emulsion, an aqueous clarified stillage, and a protein paste. The protein paste may be dried to generate a high protein animal feed with greater than about 45% protein content. The clarified thin stillage is condensed to yield a syrup with greater than around 60% solids. The oil emulsion is subjected to a pH adjustment to liberate the oil from the emulsion, which is then separated.

CROSS-REFERENCE

This application is a U.S. national stage filing of Patent CooperationTreaty (PCT) application serial number PCT/US2012/033346 entitled“SYSTEMS AND METHODS FOR STILLAGE FRACTIONATION” filed on Apr. 12, 2012,which claims the benefit of U.S. Provisional Application Ser. No.61/476,702, filed Apr. 18, 2011, and entitled “SYSTEMS AND METHODS FORSTILLAGE FRACTIONATION”, the entirety of which are expresslyincorporated herein by reference.

FIELD

The subject disclosure relates to systems and methods for fractionatingthin and whole stillage in an ethanol production facility.

BACKGROUND

Ethanol traditionally has been produced from grain-based feedstocks(e.g., corn, sorghum/milo, barley, wheat, soybeans, etc.), or from sugar(e.g., sugar cane, sugar beets, etc.).

In a conventional ethanol plant, corn, sugar cane, other grain, beets,or other plants are used as a feedstock and ethanol is produced fromstarch contained within the corn, or other plant feedstock. In the caseof a corn facility, corn kernels are cleaned and milled to preparestarch-containing material for processing. Corn kernels can also befractionated to separate the starch-containing material (e.g.,endosperm) from other matter (such as fiber and germ). Initial treatmentof the feedstock varies by feedstock type. Generally, however, thestarch and sugar contained in the plant material is extracted using acombination of mechanical and chemical means.

The starch-containing material is slurried with water and liquefied tofacilitate saccharification, where the starch is converted into sugar(e.g., glucose), and fermentation, where the sugar is converted by anethanologen (e.g., yeast) into ethanol. The fermentation product isbeer, which comprises a liquid component, including ethanol, water, andsoluble components, and a solids component, including unfermentedparticulate matter (among other things). The fermentation product issent to a distillation system where the fermentation product isdistilled and dehydrated into ethanol. The residual matter (e.g., wholestillage) comprises water, soluble components, oil, and unfermentedsolids (e.g., the solids component of the beer with substantially allethanol removed, which can be dried into dried distillers grains (DDG)and sold, for example, as an animal feed product). Other co-products(e.g., syrup and oil contained in the syrup) can also be recovered fromthe whole stillage.

In a typical ethanol plant, a massive volume of whole stillage isgenerally produced. In fact, for a typical ethanol plant the amount ofwhole stillage produced can be nearly 13.4 gallons per bushel of cornprocessed. Roughly, a third of the corn feedstock is present in thewhole stillage as dissolved and suspended solids. The stillage containsalmost 90% water. Whole stillage is responsible for a substantialportion of the wastewater generated by ethanol plants. The financialcost of the water, its treatment and disposal (typically throughevaporation) can be significant.

While stillage is typically viewed as a liability for an ethanol plant,it is possible to generate a number of high value co-products from thestillage. For example, oil in stillage, high protein feeds, and syrupsare all able to be generated from stillage and sold as higher valueco-products. Currently, in the interest of improving efficiencies ofethanol plants, whole stillage is often separated into two components: asolid component and a liquid component. Separation may be performedusing centrifugation, or filter and press. The solid component may bedried to generate dried distillers grain (DDG) which is sold as animalfeed. The liquid component, known as thin stillage, may be dried andused to increase the fat content of DDG to make DDGS (Distillers DriedGrains with Solubles). This process requires the drying of a largeamount of water, which is very energy intensive and costly. Thinstillage may also be recycled into the plant, such as for replacement ofsome portion of the water used during fermentation (fermentationbackset).

Further, there is currently a strong push to generate corn oil fromstillage, as oil is a particularly high value commodity, and forregulatory and legal considerations. Ideally, an ethanol plant wouldgenerate a minimum of 1.33 pounds of oil product per bushel of cornprocessed. A number of oil recovery methods are known, but to date nonehas achieved more than about one pound of oil per bushel. Further,conventional processes for recovering oil from fermentation productsoften sacrifice oil quality such that the oil contains high levels offree fatty acids. The presence of a high level of free fatty acids canhamper the production of end products such as, for example, the yieldand quality of any bio-diesel eventually produced with the oil as afeedstock.

For example, the patent application PCT/US 2009/045163 (entitled“METHODS FOR PRODUCING A HIGH PROTEIN CORN MEAL FROM A WHOLE STILLAGEBYPRODUCT AND SYSTEM THEREFORE”) discloses a process for separatingwhole stillage into a solid portion and a thin stillage. The thinstillage is again separated to a protein and a water-soluble portion. Anoil fraction may be separated from the water portion via evaporation. Inthe method of the PCT application, oil is recovered post evaporation,which likely results in yield reductions and oil quality sacrifices.

Another current method of oil recovery is disclosed by U.S. Pat. No.7,829,680 (entitled “SYSTEM AND METHOD FOR ISOLATION OF GLUTEN AS ACO-PRODUCT OF ETHANOL PRODUCTION”). In this method, a plurality ofscreens is utilized to separate a fiber product from an oil/proteinproduct. The oil and protein may then be separated via centrifugation.

While these known systems and methods may generate valuable co-productsfrom ethanol production stillage, they have inherent drawbacks relatedto oil quality, quantity of oil recovered, water balance issues, andcomposition of the protein products isolated.

SUMMARY

The disclosed aspects relate to systems and methods for fractionatingwhole stillage from an ethanol production facility. The system offractionation generates multiple valuable co-products while reducing thedemand for energy over many traditional methods of treatment ofstillage.

In the disclosed systems and methods, the whole stillage undergoes aseparation of its liquid portion (thin stillage) from its solid portion(fiber cake). This separation may be performed utilizing membranes,screw presses, centrifuges, or other suitable means. In someembodiments, the solids and liquids in whole stillage may be separatedutilizing a screening centrifuge.

The fiber cake may be dried to generate a high fiber animal feed. Thethin stillage may be provided to a three-phase separator for separationinto an oil emulsion, an aqueous clarified stillage, and a proteinpaste. In some embodiments, the three-phase separator may include a disknozzle centrifuge or other suitable separator device.

The protein paste may be dried to generate a high protein animal feed.In some cases, this feed may have greater than about 45% proteincontent. In alternate embodiments, the protein paste may be returned tothe fiber cake prior to drying in order to alter the nutritional makeupof the animal feed produced.

The clarified thin stillage may be utilized as fermentation backset, orother makeup water source, within an ethanol production facility, forexample. Alternatively, some or all of the clarified stillage may becondensed, utilizing an evaporator or other suitable device, to yield asyrup. The syrup (high solid syrup) may be utilized as an animal feedproduct. Generally, the syrup may contain between about 30% and about40% moisture, greater than about 10% protein, less than about 1% fiber,between about 6% and about 10% fat, and between about 5% to about 7%ash.

The oil emulsion may be subjected to a pH adjustment to liberate the oilfrom the emulsion. The pH adjustment may utilize a caustic to bring theemulsion pH to about 8.0 to about 8.5. The oil can be separated from theemulsion utilizing a centrifuge, or other suitable separating device.The oil resulting may include greater than about 97% fat. Further, insome embodiments, about 1.33 or more pounds of oil may be recovered fromthe whole stillage generated from processing a bushel of corn forethanol.

Note that the various features of the various aspects described abovemay be practiced alone or in combination. These and other features willbe described in more detail below in the detailed description and inconjunction with the following figures.

DESCRIPTION OF THE DRAWINGS

In order that the various aspects may be more clearly ascertained, someembodiments will now be described, by way of example, with reference tothe accompanying drawings, in which:

FIG. 1 is a perspective view of a biorefinery comprising an ethanolproduction facility, in accordance with some embodiments;

FIGS. 2A and 2B are process flow diagrams illustrating examples ofethanol production processes from corn to ethanol, in accordance withsome embodiments;

FIG. 3 is a schematic block diagram illustrating a system forfractionating stillage, in accordance with some embodiments;

FIG. 4 is an example flowchart illustrating a process of fractionatingstillage into valuable co-products, in accordance with some embodiments;

FIG. 5 lists experimental compositions of stillage fractions, inaccordance with some embodiments; and

FIG. 6 lists expected compositions of commercially derived stillagefractions, in accordance with some embodiments.

DESCRIPTION OF THE EMBODIMENTS

The various aspects will now be described in detail with reference toseveral embodiments thereof as illustrated in the accompanying drawings.In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the various aspects. Itwill be apparent, however, to one skilled in the art, that embodimentsmay be practiced without some or all of these specific details. In otherinstances, well known process steps and/or structures have not beendescribed in detail in order to not unnecessarily obscure the disclosedaspects. The features and advantages of embodiments may be betterunderstood with reference to the drawings and discussions that follow.

The following description relates to systems and methods forfractionating stillage from an ethanol production plant or otherprocessing facility. Ethanol plants generate large quantities ofstillage as a low value product. Stillage is generally a low valueco-product that requires substantial energy to dry into solubles foraddition to distillers dried grains, or must be disposed of in someother manner. There is the potential for the generation of high valueco-products from stillage, thus, the disclosed aspects provide forsystems and methods that improve stillage utilization, which cangenerate multiple high quality co-products without unduly influencingthe water balance of the ethanol production facility. Such systems andmethods can provide increased revenue from co-products and a lowerimpact on the environment.

The disclosed systems and methods provide a means to substantiallyimprove the quality and value of stillage by fractionating the stillageinto components, each highly valued in their own right. The fractionsgenerated by the disclosed systems and methods, in addition to beingintrinsically valuable, provide an improved water balance for theethanol production facility, thereby reducing the energy required toprocess the stillage over traditional evaporation and drying.

Referring to FIG. 1, an example biorefinery 100 comprising an ethanolproduction facility configured to produce ethanol from corn is shown.The example biorefinery 100 comprises an area 102 where corn (or othersuitable material including, but not limited to, biomass, sugars, andother starch products) is delivered and prepared to be supplied to theethanol production facility. The ethanol production facility comprisesapparatus 104 for preparation and treatment (e.g., milling) of the corninto corn flour suitable for fermentation into fermentation product in afermentation system 106. The ethanol production facility comprises adistillation system 108 in which the fermentation product is distilledand dehydrated into ethanol. The biorefinery may also comprise, in someembodiments, a by-product treatment system 110 (shown as comprising acentrifuge, a dryer, an evaporator, and associated tanks).

Referring to FIGS. 2A and 2B, in an ethanol production process, corn 202(or other suitable feed material) may be prepared for further treatmentin a preparation system 204. As illustrated in FIG. 2B, the preparationsystem 204 may comprise cleaning or screening 206 to remove foreignmaterial, such as rocks, dirt, sand, pieces of corn cobs and stalk, andother unfermentable material (e.g., removed components). After cleaningor screening 206, the particle size of corn may be reduced by milling208 to facilitate further processing. The corn kernels may also befractionated into starch-containing endosperm, fiber, and germ, inaccordance with some embodiments. The milled corn 210 or endosperm isslurried with water, enzymes and agents 212 to facilitate the conversionof starch into sugar (e.g. glucose), such as in a first treatment system214. The sugar (e.g., treated component 216) is converted into ethanolby an ethanologen (e.g. yeast or other agents 218) in a fermentationsystem 220. The product of fermentation (fermentation product 222) isbeer, which comprises a liquid component, including ethanol and waterand soluble components, and a solids component, including unfermentedparticulate matter (among other things). The fermentation product may betreated with agents 224 in a second treatment system 226. The treatedfermentation product 228 is sent to a distillation system 230. In thedistillation system 230, the (treated) fermentation product is distilledand dehydrated into ethanol 232. In some embodiments, the removedcomponents 234 (e.g., whole stillage), which comprise water, solublecomponents, oil, and unfermented solids (e.g., the solids component ofthe beer with substantially all ethanol removed), may be dried intodried distillers grains (DDG) in a third treatment system (where theremoved components may be treated with agents) and sold as an animalfeed product. Other co-products, for example, syrup (and oil containedin the syrup), may also be recovered from the stillage, as will bedescribed in further detail below.

In some systems, the thin stillage that results when solids are removedfrom the whole stillage can be used as a backset during the fermentationprocess and also can be used to increase the fat content of DDGS(Distillers Dried Grains with Solubles). However, the addition of thinstillage to DDGS requires costly evaporation processes that increase theDDGS production cost. Disclosed herein are systems and methods forfractionating the whole stillage in order to generate relevantquantities of valuable co-products in a manner which ultimately reducesthe required fuel spent on evaporation.

Referring now to FIG. 3, an example schematic block diagram of a systemfor fractionation of the removed stillage component is provided. In thisexample diagram, the whole stillage 302 is provided to a stillage filter304 for separation of the stillage into a solids component and a liquidthin stillage 306. The separation may be performed through screw press,centrifugation, decanters, or via filtration type methodologies. In someparticular embodiments, the separation may be performed utilizing ascreen bowl centrifuge. One of ordinary skill in the art will appreciatethat the speed or amount of centrifugal force applied will depend onvarious factors such as sample size and may be adjusted appropriatelydepending on such factors. Suitable separators and centrifuges areavailable from various manufacturers such as, for example, Seital ofVicenza, Italy, Westfalia of Oelde, Germany or Alfa Laval of Lund,Sweden.

The solid component comprises a high fiber cake 308, which may be driedat a dryer 310 to a high fiber dried distillers grain (DDG) 312 product.Such high fiber DDG may be particularly suited for the poly-gastricanimal feed markets (ruminant feed). In some embodiments, the fiber cakemay additionally undergo a washing step prior to being dried. The washfluid may be combined with the liquid thin stillage, in someembodiments.

Separation of the fiber cake solids from the thin stillage may beperformed soon after initial production of the fermentation product(whole stillage) in order to maintain co-product composition quality andto prevent undue exposure of the co-products to heat, oxygen, andpotential contaminants. If the whole or thin stillage is left exposedfor extended periods of time in the presence of moisture, hydrolysis ofthe oils may occur which leads to the formation of free fatty acids,which degrades the quality of oil produced.

The resulting liquid thin stillage 306 is provided to a three phaseseparator 314, which may include a disk nozzle type centrifuge orsuitable filtration type system. The three phase separator 314 separatesthe thin stillage 306 into a top layer of oil emulsion 318, a middleaqueous clarified thin stillage 320, and a protein paste 322. One ofordinary skill in the art will appreciate that the speed or amount ofcentrifugal force applied will depend on various factors such as samplesize and may be adjusted appropriately depending on such factors.Suitable separators and centrifuges are available from at least themanufacturers listed above.

The protein paste 322 may be dried in a dryer 324 to a high protein DDGproduct 326. The high protein DDG may be particularly suited formono-gastric (non-ruminant) and young animal feed. The high protein DDGmay have high metabolizeable energy and a lysine content of betweenabout 2% and about 3%, which can be important in feed rationformulations.

The clarified thin stillage 320 may be condensed through evaporation 328or concentrated by reverse osmosis to yield high solid syrup 330. Due tolow levels of suspended solids in the clarified thin stillage, hightotal solids can be achieved in a concentrated syrup without substantialviscosity limitations. The high solids syrup 330 may have between about30 and 80 percent solids, dependent upon material handling propertiesdesired, as well as end use. In some particular embodiments, the highsolid syrup may contain greater than around 60% solids. High solid syrup330 may be marketed as a high energy animal feed supplement. Inalternate embodiments, some portion of the clarified thin stillage maybe utilized as a backset for fermentation, thereby further reducing theneed for evaporation further.

The oil emulsion 318 may be pH treated by an alkali in order to disruptthe emulsion. The adjustment of pH may be critical for the liberation ofthe oil from emulsion, and may result in greater oil yields and enhancedoil quality. Particularly, adjusting the pH of the oil fractionseparates or breaks the oil fraction such that the resulting oilrecovered has a low fatty acid content. The age of the fermented productand the organic acid content of the fermented product can affect theoptimum pH for separation, however, the oil fraction is treated with thehighest pH possible to reduce the overall free fatty acid content in theseparated oil without sacrificing oil quality. In some embodiments, thepH is adjusted to a range of about 7 to about 10. In some particularembodiments, the pH is adjusted to between around 8.0 and around 8.5.

Oil 332 may be separated from the remaining emulsion/aqueous layerthrough centrifugation, filtration, distillation or other suitableseparator 334. The remaining aqueous layer/emulsion may be high inprotein and recycled for addition to DDG or sold as a separate feedproduct.

The oil composition recovered from the aspects described herein may befurther processed in a variety of ways. For example, the crude oil maybe filtered and bleached to provide a food grade oil for consumer use.In one embodiment, the crude oil may be degummed, further causticrefined, and subjected to a soap removal step according to commerciallyavailable processes. Following these steps, the oil may be subjected toone or more clay bleaching steps to achieve an oil of desired contentand color. If one or more clay bleaching steps are used, the clay may bean acid clay or a non-acid clay. In one embodiment, the bleaching stepmay include, by way of example, an acid clay or a non-acid clay ataround 1% to around 5% based on the total weight. In addition to or asan alternative to clay bleaching, after the crude oil has been degummed,caustic refined and subjected to a soap removal step, a food grade oilof a desired color may be achieved using a heat bleaching step.

The oil composition can be used in a wide variety of applications. Suchexemplary applications include the areas of oleochemicals, feed (e.g.,animal feed) as well as oils suitable for human consumption.Oleochemicals include feedstock chemicals that are suitable forbiodiesel production (fatty acid methyl esters). Industrialoleochemicals are useful in the production of soaps, detergents, wireinsulation, industrial lubricants, leather treatments, cutting oils,mining agents for oil well drilling, ink removal, plastic stabilizers,ink, and in rubber production. Other industrial applications includewaxes, shampoos, personal hygiene and food emulsifier or additiveproducts. It is also possible in some embodiments, to pre-treat oil fordownstream uses, such as conversion to bio-diesel.

The recovered oil composition can contain low levels of moisture,insolubles and unsaponifiables (MIU content). Moisture, as contemplatedherein, includes water and any volatile material such as, for example,hexane, ethanol, methanol, or a combination thereof. Insoluble matter(i.e., “insolubles”), as contemplated herein, refers to and includes anymatter incapable of being dissolved in the aqueous portion, oil fractionor oil composition. Unsaponifiable matter (i.e., “unsaponifiables”)includes any variety of possible non-triglyceride materials that act ascontaminants during bio-diesel production. Usaponifiable matter cansignificantly reduce the end product yields of the oil composition andcan, in turn, reduce end product yields of processes such as, forexample, bio-diesel production processes.

Maintaining low levels of moisture is especially desirable becausemoisture fosters the formation of free fatty acids instead of esters. Inone embodiment, the oil composition contains no greater than around 1%w/w of total moisture content, alone, based on the total weight of theoil composition. In some embodiments, the moisture content, alone, is nogreater than about 0.5% w/w or about 0.1% w/w.

In one embodiment, the oil composition comprises no greater thanapproximately 3% w/w of unsaponifiables, based on the total weight ofthe oil composition. In some embodiments, the oil composition comprisesno greater than around 2% w/w or around 1% w/w of unsaponifiables.

In one embodiment, the oil composition contains no greater than about 1%w/w insolubles, alone, based on the total weight of the oil composition.In some embodiments, the insolubles content, alone, is no greater thanapproximately 0.5% w/w or approximately 0.1% w/w.

The oil composition may, in some embodiments, exhibit an iodine valueacceptable for bio-diesel production and, in some embodiments, exhibitsan iodine value higher than that expected from a neat oil sample. Theoil can further comprise various carotene, carotenoid, and antioxidantor neutraceutical compounds.

In one embodiment, the oil composition contains no greater than about 5%w/w free fatty acid content, based on the total weight of the oilcomposition. In some embodiments, the free fatty acid content, is nogreater than around 3% w/w.

The fatty acid content of the oil composition is comprised of variousfatty acids known in the art. In one embodiment, the oil compositioncomprises C 16 palmitic acid which represents no greater than about 15%w/w of the total fatty acid content, based on the total weight of theoil composition. In another embodiment, the C 16 palmitic acid contentis no greater than around 10% w/w of the total fatty acid content. Inone embodiment, the oil composition comprises C 18 stearic acid whichrepresents at least about 3% w/w of the total fatty acid content, basedon the total weight of the oil composition. In another embodiment, theC18 stearic acid content is at least about 1.5% w/w of the total fattyacid content. In one embodiment, the oil composition comprises C18-1oleic acid which represents at least around 30% w/w of the total fattyacid content, based on the total weight of the oil composition. Inanother embodiment, the C18-1 oleic acid content is at least about 25%w/w of the total fatty acid content. In one embodiment, the oilcomposition comprises C18-2 linoleic acid which represents at leastaround 60% w/w of the total fatty acid content, based on the totalweight of the oil composition. In another embodiment, the C18-2 linoleicacid content is at least around 50% w/w of the total fatty acid content.In one embodiment, the oil composition comprises C 18-3 linolenic acidwhich represents no greater about 1.5% w/w of the total fatty acidcontent, based on the total weight of the oil composition. In anotherembodiment, the C18-3 linolenic acid content is no greater than about0.5% w/w of the total fatty acid content.

Since the entire thin stillage is not evaporated, in these embodiments,there is substantial fuel and cost savings over traditional stillagehandling which includes the substantial evaporation of the thin stillagefor addition back to the DDG to generate dried distillers grains withsolubles (DDGS). As such, not only are greater quantities of highervalue products generated through the disclosed treatment of the wholestillage, but additionally, the process utilizes less fuel therebyreducing pollution generated and reducing operational costs.

FIG. 4 provides an example flow diagram 400 for the process ofgenerating high value co-products. In this process, the whole stillageis separated into solids and the liquid thin stillage (at 402). Thesolids include a fiber cake which is dried (at 404) to a high fiberdried distiller grain (HF-DDG) co-product.

In some embodiments, due to the composition of the fiber cake, there isless water retention of the product after separation of the thinstillage and washing. As the fiber cake includes less water, there is asubstantial reduction in drying costs associated with the production ofthe high fiber dried distiller grain (HF-DDG) co-product over a moretraditional DDG product. In some embodiments, the solid content of thefiber cake may be as high as between around 40% to around 45% solidsbefore drying, as opposed to a wet cake (used to make conventional DDG)which typically includes only about 30% to around 35% solids prior todrying.

In some embodiments, the thin stillage is fractionated (at 406) into anoil emulsion, a protein paste, and a clarified thin stillage. Theprotein paste, which includes a high lysine content, is dried (at 408)to generate a high protein dried distillers grain (DDG HP). In someembodiments, the protein paste may also be returned to the fiber cakeand dried together to generate an enhanced DDG product. Handling of theprotein paste may be determined by market considerations, and equipmentavailable at the ethanol production facility.

The thin stillage may then be condensed (at 410) to a high solidscontent (e.g., between around 30 to 80 percent solids) to generate ahigh solids syrup. High solids syrups are usable as an effective animalfeed substitute, however the generation of practical high solid syrupmay be difficult to obtain. This is because most syrups generated fromthin stillage, once the solid content approaches about 30 percent,become prohibitively viscous, and are unusable as a marketableco-product. By processing the thin stillage to a clarified thinstillage, ultra high solids content (e.g., greater than about 30%) isachievable in a syrup which retains a viscosity of molasses. Thus, theco-product is easily transported and handled by prospective buyers.

Lastly, the oil emulsion is treated to extract valuable oil (at 412).Oil extraction is facilitated by pH adjusting the emulsion with analkali. The addition of the caustic agent disrupts the emulsion andliberates the oil. The liberated oil may be extracted from the remainingemulsion via decanting, centrifugation, filtration or other suitablemethod. In some embodiments, greater than about 1.33 pounds of corn oilare achieved per bushel of corn utilizing the disclosed embodiments.

A series of limited examples were conducted according to an exemplaryembodiment of the system (as shown in FIG. 3) in an effort to determinesuitable apparatus and operating conditions for the fractionation ofwhole stillage. The following examples are intended to provide clarityto some embodiments of systems and means of operation; given the limitednature of these examples, they do not limit the scope of the disclosedaspects.

Example 1

In this example experiment, whole stillage was screened utilizing ascreen centrifuge in order to obtain a fiber cake and thin stillage. Thefiber cake was dried and tested for composition. The thin stillage wasfurther processed by decanter centrifuge to yield an oil emulsion,clarified thin stillage and a protein paste. The protein paste wasdried. The clarified thin stillage was evaporated to over 60% solidscontent. The oil emulsion was treated using a caustic agent to adjustthe pH to about 8. The oil emulsion was again subjected tocentrifugation in order to remove the oil form emulsion. The oil, driedprotein paste and high solid syrup were then subjected to compositionalanalysis. The results of this analysis are provided in relation to FIG.5.

In summary, the oil product had 0.9% moisture content, 3.03% free fattyacids (FFA), <0.01% insolubles, and 1.13% unsaponifiables. The highsolids syrup composition was 31.6% moisture, 10.9% protein, 0.1% fiber,6.1% ash, and 8.2% fat. The protein paste composition was 58.6% protein,12.6% fat, and <1% fiber. The high fiber DDG composition was 26.0%protein, 10% fiber, 3.5% fat, and 0.7% ash.

The yields of the four products on a percentage basis are approximately9% oil, 13% syrup, 40% protein, and 38% fiber. These yields correspondto 1.3 lb oil, 2 lb syrup, 6 lb protein, and 6 lb fiber on a pound perbushel basis. The yields expected can lead to changes to the expectedcompositions due to tradeoffs between yield and purity. The expectedcompositional ranges from commercial production of these products areshow in FIG. 6.

The embodiments as disclosed and described in the application (includingthe FIGS. and Examples) are intended to be illustrative and explanatory.Modifications and variations of the disclosed embodiments, for example,of the apparatus and processes employed (or to be employed) as well asof the compositions and treatments used (or to be used), are possible;all such modifications and variations are intended to be within thescope of the various aspects presented herein.

The word “exemplary” is used to mean serving as an example, instance, orillustration. Any embodiment or design described as “exemplary” is notnecessarily to be construed as preferred or advantageous over otherembodiments or designs, nor is it meant to preclude equivalent exemplarystructures and techniques known to those of ordinary skill in the art.Rather, use of the word exemplary is intended to present concepts in aconcrete fashion, and the disclosed subject matter is not limited bysuch examples.

Reference throughout this specification to “one aspect,” or “an aspect,”or “one embodiment,” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the aspect orembodiment is included in at least one aspect or one embodiment. Thus,the appearances of the phrase “in one aspect,” or “in an aspect,” or “inone embodiment,” or “in an embodiment” in various places throughout thisspecification can, but are not necessarily, referring to the same aspector embodiment, depending on the circumstances. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more aspects or embodiments.

The term “or” is intended to mean an inclusive “or” rather than anexclusive “or.” To the extent that the terms “comprises,” “has,”“contains,” and other similar words are used in either the detaileddescription or the claims, for the avoidance of doubt, such terms areintended to be inclusive in a manner similar to the term “comprising” asan open transition word without precluding any additional or otherelements.

What is claimed is:
 1. A process for fractionating whole stillagecomprising: a first separator separating whole stillage to a solidportion and a thin stillage liquid portion, wherein the solid portioncomprises a fiber cake; a three phase separator receiving the thinstillage liquid portion and separating the thin stillage liquid portionto a clarified stillage, an oil emulsion and, a protein paste; a firstdryer drying the fiber cake to generate a fiber animal feed product; asecond dryer drying the protein paste to generate a protein animal feedproduct; an evaporator condensing the clarified stillage to a syrup; asecond separator separating oil from the oil emulsion; and a pH adjusteradjusting pH of the oil emulsion prior to separation by the secondseparator.
 2. The process of claim 1, wherein the pH adjuster adjuststhe pH of the oil emulsion to about 8.0 to about 8.5.
 3. The system ofclaim 1, wherein the second separator separates at least 1.33 pounds ofoil from the whole stillage generated from processing a bushel of cornfor ethanol.
 4. The system of claim 1, wherein the evaporator condensesthe clarified stillage to at least 60% solids.
 5. The system of claim 1,wherein the second dryer dries the protein paste to generate a proteinanimal feed product with at least 45% protein.
 6. The system of claim 1,wherein the second separator separates oil with at least 97% fat.
 7. Thesystem of claim 6, wherein the second separator separates oil with lessthan 1% w/w moisture content and less than 1% w/w insolubles.
 8. Theprocess of claim 6, wherein the second separator separates oil with lessthan 5% w/w free fatty acid content.
 9. A method for fractionatingstillage comprising: separating whole stillage to a solid portion and athin stillage liquid portion, wherein the solid portion includes a fibercake; separating the thin stillage into a clarified stillage, an oilemulsion, and a protein paste; drying the fiber cake to generate a fiberanimal feed product; drying the protein paste to generate a proteinanimal feed product; condensing the clarified stillage to generate asyrup; separating oil from the oil emulsion; and adjusting pH of the oilemulsion prior to separating the oil.
 10. The method of claim 9, whereinthe adjusting comprises adjusting pH of the oil emulsion to about 8.0 toabout 8.5.
 11. The method of claim 9, wherein at least around 1.33pounds of oil is separated from the whole stillage generated fromprocessing a bushel of corn for ethanol.
 12. The method of claim 9,further comprising combining at least some portion of the protein pastewith the fiber cake.
 13. The method of claim 9, wherein the condensingcomprises condensing the syrup to at least about 60% solids.
 14. Themethod of claim 9, wherein the protein animal feed product comprises atleast about 45% protein.
 15. The method of claim 9, wherein the oilcomprises at least about 97% fat.
 16. The method of claim 15, whereinthe oil comprises less than 1% w/w moisture content and less than 1% w/winsolubles.
 17. The method of claim 15, wherein the oil comprises lessthan about 5% w/w free fatty acid content.
 18. A process forfractionating whole stillage comprising: a first separator separatingwhole stillage to a solid portion and a thin stillage liquid portion,wherein the solid portion comprises a fiber cake; a three phaseseparator receiving the thin stillage liquid portion and separating thethin stillage liquid portion to a clarified stillage, an oil emulsionand a protein paste; a first dryer drying the fiber cake to generate afiber animal feed product; a second dryer drying the protein paste togenerate a protein animal feed product; an evaporator condensing theclarified stillage to a syrup; and a second separator separating oilfrom the oil emulsion, wherein the evaporator condenses the clarifiedstillage to at least 60% solids.